The Safer Birmingham Partnership has begun to use communications technology developed in the US to locate the source of gunfire in the city.
Birmingham is the first UK city to install the Shotspotter Gunshot Location System. The technology can locate gunshot fire within a 25-metre radius from up to 2km (1.24 miles) away. It also …

Because nobody dials 999 anymore?

How?

Now, maybe I'm being thick here, but I assume this is working through some sort of triangulation of the sound? Given that this is a city location, with plenty of buildings etc., surely the sound must rebound around so much as to make this very problematic? Also, doesn't this just make a silencer the object of desire in Birmingham?

There's a ways to go

There's a reason...

...that silencers aren't called silencers.

They're known as muzzle suppressors. The soft little "ptoo" that you get from the movies is a far cry from the resounding crack of a real "silenced" firearm. They're more useful for disguising the flash than the noise.

Just like speed cameras I suppoose;

in that they could be said to "only monitor speeds when high speed is detected", ie they (generally) only record/transmit speed/numberplate data* when their internal logic is activated by a speed >x.

It would be trivial and the best technical solution to have each of the microphones in the network sit dormant until activated by a sound >XdB, and then they begin processing/recording the sound input and transmitting the appropiate data to HQ.

I imagine the processing involves a little DSP to differentiate 'gunshot' type cracks from all other loud noises, and precise timing of the sound against something like a GPS clock. If you get the precise time that a given sound has reached at least 3 known points, the origin can then be calculated.

*referring to 'traditional' Gatso-type cameras, not ANPR or other hi-tech trickery.

RE: According to Beeb news..

According to the Beeb news website (http://www.bbc.co.uk/news/uk-england-birmingham-11950517), before the 12.07 update and after I enquired about it, the police were apparently quoted to saying that surveillance was not an issue as the sensors recorded decibels and not voices. Needlessly to say I was rather confused and worried by this claim. To add to this rather odd claim, the BBC news website included a clip which clearly showed that the sounds are recorded in full glory, can displayed as waveforms, analysed, and played back.

Not triangulation, its multilateration

Since you only get timing differences between receivers (you don't know exactly when the shot was fired) you need 4 points to work out where the shot came from. The first two give you one value and you get an extra one for each additional receiver.

www.shotspotter.com

Waste of money

Lets see. From newspapers I gather that the majority of inner city shootings are gang/drug related account settling so they are detecting gang on gang shootings which, quite honestly, I couldn't give two hoots about. Now compare the number of these shootings with the number of muggings which occur in Birmingham. Now think which would be more welcome by the general public, extra police patrolling the streets as a visible deterrent to prevent crime or detecting after the fact that some low life has shot on of their peers?

U

Got to be joking...

Seriously though, this sounds like a huge waste of time and money that would be far better spent on getting more coppers out of the station instead of stuck behind desks or on the sick. It's really rather scary how thin the cover is for the urban areas I know of (and I know of plenty, just don't ask me how)

The real benefit

The real benefit of installing this (no doubt expensive) system is to the employment prospects of a handful of Birmingham rozzers when they take their early retirement.

"Yes, chief inspector, I'm sure your purchase of this wonderful system will lead to the future expansion of our UK sales team"...........

Back handers are my only explanation for installation of expensive high-tech crap like those huge motorway signs which tell me "beware of spray" when is it pissing down or "14 minutes to J14" when I have no idea where J14 is.

Its not all its cracked up to be

Like all technologies it works but not in the magic/movie sense that this article implies. I can see we're going to have some fun with this system -- it responds to the crack of the gun being fired so I can see a future in tin cans / carbide and propane / air mixtures ("bird scarers") . Certainly if I were planning a hit I'd want to swamp the system, "just in case".

You've got some ace salesmen in the UK. They can sell government *anything*!

save your money

We have this system in some of the more crime-ridden areas of the city nearest to me. It DOES cost a lot, break down a lot and yes, it does find gunfire. What it does NOT do is operate effectively - CERTAINLY not effectively for the cost.

Baton Rouge, LA USA. initial cost $3.5million, annual maintenance costs over $450,000 to cover an area roughly EIGHT square miles. Birmingham should save the money and, perhaps, spend it on more [leather shoes*] on the ground.

http://www.2theadvocate.com/news/101233734.html?index=1&c=y

<excerpt>In an April 2008 e-mail, Nick Pizzalato, network administrator for the city-parish’s Information Services department, sent an e-mail to a representative of ShotSpotter.

“How can I convince the police that this is going to help them?” Pizzalato wrote. “They don’t want the system and they don’t think it’s going to be any benefit. I guess when I say they I mean the dispatchers because the field officers don’t even know about it yet.” </excerpt>

* unless, of course, the Birmingham constabulary actually DOES wear boots. Then, the old adage stands as is.

Teenagers will have a field day

Sound recognition

How long before they decide to feed in a voice print and try to match "known criminals".... and then monitor "potential terrorists"... and then say "these are required for the detection of serious and organised crime"... and then, "we heard you say you wanted to blow up the airport if they didn't stay open during the snow-storm!"

Re: Handy for

Saw it coming

I seem to remember these devices first appeared in the dystopian near-future setting of the classic video game Deus Ex. The response was simple, of course, people just killed each other with crossbows and swords instead.